HOLLYWOOD -- For a moment, Gillian Anderson seems stunned. She has had two hours' sleep. She has walked into the Hollywood dance zoo known as The Derby, a glorified jungle pit tucked away off Los Feliz Boulevard, to say hi to her good friend and mentor Chris Carter.

Carter is sitting, Buddha-like, in a red armchair, patiently answering the questions of legions of reporters who have descended like flies at a barbeque.

Anderson slips through the crowd, for one oh-so-brief moment virtually unnoticed by the hundreds of sweaty, noisy, anxious TV critics, TV fans, TV actors, TV publicists, TV friends and assorted ringers, gate-crashers and non-descript hangers-on who have crammed themselves into a space no bigger than a peewee hockey rink.

The tiny space is completely immersed in giant, noxious clouds ofsmoke -- cigarettes and dry ice: a lethal combination -- while a very big, very bad rock band called Big Bad Voodoo Daddy hammers away in the background with a hideous wailing.

Anderson appears out of nowhere, like a sweet, ghostly apparition: tan, thin, startlingly attractive -- more so than her on-screen persona -- hair tied back behind her ears, wearing casual sandals, charm bracelets on her wrists, an ankle-length, white flower-print skirt that almost hides her ankle tattoo and a short, black cardigan.

She almost makes it to Carter's chair when one of the paparazzi spots her.

The paparazzi are demanding -- not asking, demanding -- that she smile. She looks tired, bemused, turns dutifully to face the cameras and offers a sudden, tight-lipped, radiant beam, then sinks wearily beside Carter and whispers something in his ear. He laughs. The X-Files movie has been immersed in night shooting all week; the production broke for the day at 5 a.m. that morning and shooting resumes immediately after the party.

The television writer for the Oakland Tribune, one of just a handful of reporters to get near enough to Anderson to ask her a personal question, garbles her query horribly.

''I'm sorry,'' she says finally, ''I really screwed up that question. I've been here for three weeks and I'm really tired.''

''I know exactly how you feel,'' Anderson replies. Vancouver is far from her mind on this night. ''There are a couple of people there that I miss,'' she tells me coolly, ''but not Vancouver per se.''

Incredibly, the noise grows louder: Big Bad Voodoo Daddy's band members, deciding that their music is not loud enough, are beginning to screech into their microphones, which some sound geek has thoughtfully decided to crank even louder.

The Fox network is using this party to celebrate its fall- season launch, which kicks off Sept. 8 with the return of that icon of rarified sophistication, Melrose Place.

Anderson is dead tired, but gamely hangs on. She seems to be drawing strength from Carter -- ''I got four hours' sleep myself,'' he says, and laughs cheerfully -- as he patiently answers questions of throngs of reporters besieging him from all directions.

She will get just three days off after the X-Files movie has finished shooting, she says; after that, it's back to Vancouver to work on the series.

Her other movie, The Mighty, featuring Gena Rowlands and Harry Dean Stanton -- ''I play a kind of an eccentric biker alcoholic.'' she says -- will open Dec. 12.

She is contractually tied down to The X-Files for three more years, including the upcoming season. No, she will not consider another TV series after that.

"I'm not interested,'' she says. ''I wasn't interested in doing television to begin with. I appreciate it, but I'd like to get out of it as fast as possible.''

It's not been that difficult dealing with X-Files fans, she insists. ''It's been more difficult dealing with the paparazzi and the press. ''There are a lot of fans out there, but then there are a lot of people in the world. Everybody I've dealt with has been very kind.''

Anderson's manager, agent, chaperon and confidante, Connie Frieberg, hovers near her charge like a protective mother guarding her offspring.

Which begs the question: Since Anderson is coming off just two hours' sleep in the last 24, why is she here?

Simple, Frieberg says: The Television Critics Association nominated 11 actors for its first-ever awards for individual achievement in acting. Of those 11 actors, Anderson was the only woman. Showing up at the Fox party, two hours sleep or not, is Anderson's way of acknowledging that recognition.

Even so, she is beginning to fade.

When The X-Files finally fades into TV's storied past, I ask her, what one enduring memory will she carry with her from her years on the show?

''I'm not quite sure how to answer that question,'' she replies after a long pause. ''I'm not quite sure what the question is.'' Later, after Anderson has gone -- she slips away into the night, Carter, serene as always, stands up to leave.

He's appeared so serene, I tell him, that he could be mistaken for being in a Buddhist trance.

''I am hardly in a Buddhist trance,'' he replies.

In another corner of the smoke-choked lounge, The X-Files' Cigarette-Smoking Man, Bill Davis, flown down from Vancouver with Lone Gun Dean Haglund and Tom Braidwood especially for the event, is trying to look as inconspicuous as possible.